Aircraft having drag reducing means



' 1954 L. SCHWARZMAYR AIRCRAFT HAVING DRAG REDUCING MEANS Filed July 28,1953 Patented Oct. 26, 1954 UNITED STATES PATENT OFFICE AIRCRAFT HAVINGDRAG REDUCING MEANS Ludwig Schwarzmayr, San Francisco, Calif.

Application July 28, 1953, Serial No. 370,743

4 Claims. 1

My invention relates to improvements in aircraft constructions.

One object of my invention is to prevent formation of a low pressurezone in the trailing zone of the fuselage.

Another object is to make possible reduction of Weight of the fuselageby providing the fuselage with an antidrag air supplier maintaining astreamlined body of air behind the fuselage, thereby making a longstreamlined rear portion of the fuselage unnecessary.

I attain these objects by the constructions illustrated in theaccompanying drawings, in which- Figure l is a side elevation of theaircraft embodying my invention;

Figure 2 is the rear part of the fuselage shown in Fig. 1, andillustrating the drag preventing bodies of air formed under differentspeeds and different altitudes of travel;

Fig. 3 is a detailed vertical section of the antidrag air supplier shownin Figs. 1 and 2.

Fig. 4 is a view on line 4-4 in Fig. 3;

Fig. 5 is a front elevation of the fin shown in Figs. 1 and 2; and

Fig. 6 is a vertical section of the antidrag air supplier in a modifiedform and in conjunction with the trailing end section of a conventionafuselage.

The fuselage l of the aircraft 2 has not the conventional streamlinedtrailing section but has a trailing end 3 of abruptly converging sides4-4. An air guide 5 in the trailing end 3 of the fuselage extends intothe fin 6, and its air receiving end i is in the leading edge 8 of thefin. The air guide ii extends rearwards from the trailing end 3 of thefuselage, and has an air supplier It at the end which delivers air tothe trailing zone H of the fuselage l. The air supplier ll) has flowdirecting guides Il -H arranged to direct a fiow of air towards thetrailing end 3 of the fuselage and in the direction of flight I 2. Theforwardly projected air, illustrated by the arrows I 3-43, maintains theforwardly moving body of air 14, the outline of which is illustrated bythe broken lines l5-l5, which also indicate the outline of thestationary mass of air i6l8, which is moved against the body of air i 4by atmospheric pressure, illustrated by the arrows ll-ll. The air thatis projected forwardly towards the sides 4 by the supplier it is turnedby them towards the stationary mass of air [6, which is underatmospheric pressure 11, and the mass of air It under atmosphericpressure ll resists, and turns the air back towards the sides 4, as isillustrated by the arrows I8--|8. Therefore adjacent to the sides 4, apressure higher than the atmospheric pressure is developed. Fig. 2 isthe rear part of the fuselage shown in Fig. 1, and is of the sameconstruction, and shows the same outline of the forwards moving body ofair I4, shown in broken lines l5l5. The relatively short trailing bodyof air 14 is formed when the aircraft flies at a low rate of speed or ata low altitude, but when the aircraft flies at a high rate of speed orat a high altitude, the body of air l9 expands rearwards, as isillustrated by the broken lines 2ii-2ll. As the bodies of air [4 and I9are constantly supplied with new air by the air supplier Ill, theyexpand rearwards when the speed of the aircraft is increased or whenflying at a high altitude, and so, the bodies of air [4 and I!) areconstantly in contact with the stationary mass of air It and underatmospheric pressure ll. The frictional contact, between the stationarymass of air It and the moving bodies of air l4 and IQ, causes the outerfilm of air of these bodies of air to be dragged rearwards and be leftbehind, but this loss of air is replenished by air delivered by the airsupplier l0.

Fig. 6 is a modified form of the antidrag device in conjunction with thetrailing end 23 of a conventional fuselage 24 of an aircraft. The sides26-46 of the trailing end 23 have forwardly directed flow guides 21-21.The chamber 28 connects the flow guides 21 with the air guide 28 whichhas an air receiving end 28 in the leading edge 30 of the fin 3!. Theflow guides 21'! deliver air to the trailing zone 32 of the trailing end23, thereby, in the trailing zone 32 is maintained the body of air 33,which is under atmospheric ressure 34-3-4.

I claim:

1. In an aircraft fuselage, a trailing end, antidrag means comprising anair guide having an air receiving end and an air delivery end, said airreceiving end disposed to receive air during flight, and said airdelivery end having guide members disposed to deliver a flow of air tothe trailing zone of said trailing end in a forwardly direction.

2. In an aircraft fuselage, a trailing end, antidrag means comprising anair guide having an air receiving end and an air delivery end, said airreceiving end disposed to receive air during flight, and said airdelivery end having guide members disposed to deliver a flow of air tothe trailing zone of said trailing end in a forwardly direction againstsaid trailing end.

3. In an aircraft fuselage, a trailing end, antidrag means comprising anair guide having an air receiving end and an air delivery end, said airreceiving end disposed to receive air during flight, said air deliveryend having guide members disposed to deliver a flow of air to thetrailing zone of said trailing end in a forwardly direction against saidtrailing end, and said trailing end having relatively abruptlyconverging sides.

4. In an aircraft fuselage, a trailing end, antidrag means comprising anair guide having an air receiving end and an air delivery end, said airreceiving end disposed to receive air during flight, said air deliveryend disposed to deliver 4 a flow of air to the tnailing zone of saidtrailing end in a forwardly direction, and said air delivery endarranged in the side of said trailing end.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 2,037,942 Stalker Apr. 21, 1936 2,041,792 Stalker May 26, 19362,428,737 Crook et a1. Oct. '7, 1947 2,568,813 Lundberg Sept. 25, 19512,650,781 Taylor Sept. 1, 1953

